Disclosed herein are novel compositions, such as oral care compositions, that include metaphosphate abrasive.
Many individuals desire a “bright” smile and white teeth, and consider dull and stained teeth cosmetically unattractive. Unfortunately, without preventive or remedial measures, stained teeth are almost inevitable due to the absorbent nature of dental material. Everyday activities such as smoking or other oral use of tobacco products, and eating, chewing or drinking certain foods and beverages (in particular coffee, tea and red wine), cause undesirable staining of surfaces of teeth. Staining can also result from microbial activity, including that associated with dental plaque. The chromogens or color causing substances in these materials become part of the pellicle layer and can permeate the enamel layer. Even with regular brushing and flossing, years of chromogen accumulation can impart noticeable tooth discoloration.
There are a variety of compositions described in the art for preventing or treating the discoloration of teeth. In particular, to combat staining and brighten or restore the natural enamel color, a variety of products containing bleaching materials are commercially available for professional and consumer use. The materials most commonly used in teeth whitening today are peroxides. Peroxides are generally deemed safe from a physiological standpoint, and can be effective to whiten teeth.
Professional dental treatments frequently include a tooth surface preparation such as acid etching followed by the application of highly concentrated bleaching solutions (e.g., up to 37% hydrogen peroxide) and/or the application of heat or light. These procedures provide rapid results, but are expensive, and often require several trips to the dentist. Alternatively, at-home bleaching systems can be used. These systems have gained significant popularity in the past decade because of reduced cost, and increased convenience. Instead of time consuming and frequent trips to the dentist, the tooth whitener is purchased at a consumer retail store and may be easily integrated into the daily hygiene program. At-home treatment methods include whitening strips, abrasive toothpastes, and toothpastes that contain peroxides. These peroxide toothpastes require the use of a dual chamber system that separates the peroxide from other ingredients. If the contents of the two chambers are mixed prematurely, the oxidation activity and whitening benefits are lost. To keep peroxide components of the toothpastes stable, non-aqueous liquid carrier and peroxide friendly abrasives, such as calcium pyrophosphate have previously been used. However, changes in the type of liquid carrier have been nearly fully exploited and although calcium pyrophosphate is more stable as compared to, for example, silica and calcium carbonate, such abrasives still may contain hundreds of parts-per-million (ppm) of transition metals which act as catalysts for peroxide decomposition. Accordingly, the wt % of peroxide in the formulation must be kept considerably lower than the professional dental treatments and so whitening effect is limited.
It would be desirable to provide a whitening oral care composition which promotes consumer compliance and utilizes a single chamber or tube to deliver sufficient amounts of whitening ingredients and other oral care actives without adverse reaction between the ingredients.